With the rise in violent crimes in the United States, there is a widespread fear among the people related to their sense of security in the home and perhaps, even more important, when travelling. People staying in hotels and motels often find themselves staying in a room protected only by an inexpensive lock. Many devices have been developed to provide a greater degree of protection by providing some type of portable supplemental locing device. These devices generally fall into three main types: the portable door lock that operates with a key, as a second lock in the door; an alarm device that does not impede the operation of the door, but sounds an alarm when disturbed, and the door brace type that is mounted between the door and the floor, which then acts as a brace.
Prior art security braces for blocking entry through doorways are known. Such devices have not been widely adopted commercially for one of two reasons. The prior art devices which work effectively have been too complex and costly to be practical on the commercial market. Those devices in the prior art which are relatively simple and feasible from a cost standpoint have proven not to operate efficiently with consistency, and therefore have not been acceptable in the marketplace.
A number of patents have issued in the past which deal with door bracing devices. For example, U.S. Pat. No. 4,300,796, issued on Nov. 17, 1981, to J. L. Lane provides an adjustable door and window security prop. In this device, adjustable large and small diameter tubular members are telescopically engaged with each other. A U-shaped member is attached to one of these legs so as to engage a door handle. A stop is provided at the bottom portion of the member for frictional engagement with the floor. A lock structure is provided so as to cause fixed engagement between the tubular members.
U.S. Pat. No. 4,358,758, issued on Nov. 9, 1982, and U.S. Pat. No. 4,442,427, issued on Apr. 10, 1984, both to David C. Morton describe a combination door lock and alarm which has an upper end clip engagable with the door handle, a shaft extending in an adjustable length tube and terminating with a non-skid rubber button adapted to frictionally engage the floor. An alarm device is mounted on the shaft and includes an actuator with a switch contact normally abutting a surface of the door at a point below the door handle. The alarm sounds upon inward movement and pressure on the door. U.S. Pat. No. 4,483,558, issued on Nov. 20, 1984, to V. Van Meter shows a door security device having an elongated rod member of telescoping rod sections, a reversible foot member pivotally connected to the lower end of the rod member, and an abutment member for engaging the surface of the door beneath the door knob. An annular head is pivotally connected to the upper end of the rod member for engaging the shaft of the door knob.
U.S. Pat. No. 4,563,027, issued on Jan. 7, 1986, to Chechovsky et al. provides a door security brace which carries a pivotted foot piece at its lower end having a friction facing to prevent slippage while in contact with the floor. The brace bar carries a pivotted yoke on a pivot axis which is parallel to the foot piece pivot axis. The yoke engages the door knob shank.
U.S. Pat. No. 4,607,253, issued on Aug. 19, 1986, to Wooten et al., provides a combination door lock and alarm having an adjustable shaft, two pivot pads, and an automatic alarm. The pivot feature of the pads is designed for quick set-up of the device. The alarm utilizes a spring clip in contact with a toggle switch. The toggle switch allows for a continuous alarm signal. The alarm is actuated by a spring-loaded shaft which is pushed into the main shaft of the device as pressure is applied to the door. The spring clip is mounted on the outside of the spring-loaded shaft and the movement of this shaft is what forces the clip to trip the toggle switch.
U.S. Pat. No. 4,883,297, issued on Nov. 28, 1989, to D.R. Smith provides a power operated door guard in which an electric motor is utilized so as to cause the parts of the brace to telescope and engage the door knob and the floor.
It is an object of the present invention to provide a door locking device, with shock sensor alarm that is simple to install, easy to manufacture, and relatively inexpensive.
It is another object of the present invention to provide a door locking device which properly distributes bracing forces so as to maximize strength and protection against unauthorized entry.
It is another object of the present invention to provide a door locking device that maximizes surface friction against a floor.
It is still another object of the present invention to provide a door locking device having an alarm which is actuated by vibration.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.